Modern mobile communication devices incorporate multiple wireless interfaces. Compact dimensions of these devices cause problems with accommodating antennas, transmitters and other components inside them. Components of a mobile communication device, such as a wireless power receiver and a wireless communications unit, require a large area to accommodate inductors. A solution in this case is to dispose one inductor within the other. However, a ferrite shield of one inductor may induce variation in parameters of the other. This provokes a mismatch between the second inductor and a transceiver and affects the operation of the device.
Such impact can be taken into account where all components inside a single device are being designed at the same time. However, a simultaneous match is difficult to achieve when it is required to mount a wireless power receiver and a wireless communications unit produced by different manufacturers or when these components must operate both together and separately.
An example of this case is a mobile communication device which comprises an integrated wireless communications unit, while a wireless power receiver is mounted on a removable lid of the device housing. In this case, inductance of the wireless communications unit inductor will grow near the ferrite shield of the wireless power receiver, and as a consequence, operation of the wireless communications unit may be impaired.
U.S. Patent Application Publication Number 20100190436 A1, published on Jul. 29, 2010, U.S. Patent Application Publication Number 20050085873 A1, published on Apr. 21, 2005, U.S. Patent Application Publication Number 20090085408 A1, published on Apr. 2, 2009, U.S. Patent Application Publication Number 20120293006 A1, published on Nov. 22, 2012, and U.S. Pat. No. 8,144,066 A1, published on Aug. 26, 2010, describe concurrent operation of a wireless power transmission (WPT) system and a wireless near field communication (NFC) system at the same frequency. Currently, WPT and NFC systems operate on different frequencies. Alliance for Wireless Power (A4WP) Technical Specification (see http://www.a4wp.org) provides for operation of wireless power devices at 6.78 MHz, while the NFC operating frequency is 13.56 MHz. The devices described in the above documents do not support operation at two different frequencies.
Another method, described by Dionigi M., Mongiardo M., “Multi band resonators for wireless power transfer and near field magnetic communications”, Microwave Workshop Series on Innovative Wireless Power Transmission: Technologies, Systems, and Applications (IMWS), Institute of Electrical and Electronics Engineers (IEEE) 2012 Microwave Theory and Techniques Society (MTT-S) International, Kyoto, 2012, comprises using a resonator with multiple natural frequencies for concurrent operation in two bands. The method assumes that WPT and NFC systems are incorporated in a single device, so the method cannot be used in existing devices where an NFC system can be already integrated, while WPT system is mounted on a removable lid.
Literature relating to this issue predominantly describes methods of providing wireless power reception concurrently with wireless data transfer through integration of WPT system and wireless data transfer system together in a single device such that they cannot be separated from the device. No description of a method providing WPT and NFC systems which are capable of operating both together and separately has been found.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.